* enable writing messages using org-mode, on-fly conversion to html, document it

emacs/mu4e.texi

@@ -1327,6 +1327,7 @@ with other tools.
 @menu
 * Setting the default emacs mail program::
 * Creating org-mode links::
+* Rich-text messages with org-mode::
 * Maintaining an address-book with org-contacts::
 * Getting new mail notifications with Sauron::
 * Speedbar support::
@@ -1369,6 +1370,50 @@ to the query or message the link points to with either @t{M-x
 org-agenda-open-link} in agenda buffers, or @t{M-x org-open-at-point}
 elsewhere - both are typically bound to @kbd{C-c C-o}.
 
+@node Rich-text messages with org-mode
+@section Rich-text messages with org-mode
+
+@t{org-mode} has some nice facilities for editing texts -- creating lists,
+tables, mathematical formulae etc. In addition, it can convert them to
+@abbr{HTML}.
+
+An @emph{experimental} @t{mu4e} feature lets you edit your messages with
+@t{org-mode}, and (optionally) convert them on the fly (when sending them) to
+messages with an HTML-part containing the rich-text version of your messages.
+ 
+To enable all this, make sure you have
+@lisp
+(require 'org-mu4e)
+@end lisp
+somewhere in your setup, and also make sure that the @t{dvipng} program is
+available in your path.
+
+Then, when composing a message, you can use @code{M-x
+org-mu4e-compose-org-mode} to enable this mode, or, alternatively, put in the
+mode-hook for @t{mu4e-compose-mode}.
+
+@t{org-mu4e-compose-org-mode} behaves more or less like a minor-mode. When it
+is active, editing the message body takes place in @t{org-mode}, while editing
+the headers uses the normal message editing mode, @t{mu4e-compose-mode}.
+
+Now, if you want to automatically convert the @t{org-mode} markup to rich-text
+when sending messages, you need to set the variable
+@code{org-mu4e-convert-to-html} to non-nil:
+
+@lisp
+(setq org-mu4e-convert-to-html t)
+@end lisp
+
+To send the message or execute other @t{mu4e-compose-mode}/@t{message-mode}
+commands on the message, first press @key{M-m}. Thus, for example, to send the
+message, you'd press @key{M-m C-c}.
+
+The code for doing the conversion is based on Eric Schultze's
+@t{org-mime}@footnote{@url{http://orgmode.org/worg/org-contrib/org-mime.php}},
+but has been customized for use with @t{mu4e}. In particular, the
+mode-switching between @t{org-mode} and @t{mu4e-compose-mode} is
+@t{mu4e-specific}.
+
 @node Maintaining an address-book with org-contacts
 @section Maintaining an address-book with org-contacts